The F2P game World of Tanks, is a fun, fast paced, tank simulation game... with the most gut wrenchingly drawn out grinding process ever devised. before moving up a tier, you need to invest a shit-ton of time grinding for experience, just to be able to unlock the ability to buy the next tank, let alone pay for it. Also, when you finally buy the new tank, the parts you initially start out with make you shittier than you were previously, thus more grinding just to make your tank not suck. you also need to buy ammunition, which, if you dont want to suck, means grinding to buy the better shells. However, if you want to pay real world cash, you can skip the grinding. (but thats for pussies.) It is stiff a very fin game though.